Fukushima scaremongers becoming increasingly desperate

The situation at the quake- and tsunami-stricken Fukushima Daiichi nuclear powerplant in Japan was brought under control days ago. It remains the case as this is written that there have been no measurable radiological health consequences among workers at the plant or anybody else, and all indications are that this will remain the case. And yet media outlets around the world continue with desperate, increasingly hysterical and unscrupulous attempts to frame the situation as a crisis.

Here's a roundup of the latest facts, accompanied by highlights of the most egregious misreporting.

First up, three technicians working to restore electrical power in the plant's No 3 reactor building stood in some water while doing so. Their personal dosimetry equipment later showed that they had sustained radiation doses up to 170 millisievert. Under normal rules when dealing with nuclear powerplant incidents, workers at the site are permitted to sustain up to 250 millisievert before being withdrawn. If necessary, this can be extended to 500 millisievert according to World Health Organisation guidance.

None of this involves significant health hazards: actual radiation sickness is not normally seen until a dose of 1,000 millisievert and is not common until 2,000. Additional cancer risk is tiny: huge numbers of people must be subjected to such doses in order to see any measurable health consequences. In decades to come, future investigators will almost certainly be unable to attribute any cases of cancer to service at Fukushima.

Nonetheless, in the hyper-cautious nuclear industry, any dose over 100 millisievert is likely to cause bosses to pull people out at least temporarily. Furthermore, the three workers had sustained slight burns to their legs as a result of standing in the radioactive water - much as one will burn one's skin by exposing it to the rays of the sun (a tremendously powerful nuclear furnace). They didn't even notice these burns until after completing their work. Just to be sure, however, the three were sent for medical checks.

Reporters clamoured to know more - in particular how could the water in the basement of the reactor building have become so radioactive - no less than "10,000 times normal". One might note that in general radiation levels 10,000 times normal mean that you could achieve a tiny fraction of an extra percentage point of cancer risk by being exposed for a fortnight or so.

Japanese government spokesmen briefing the press obligingly gave a list of possibilities. Among these was the possibility that the suppression chamber at No 3 may be leaking water or steam due to damage (as well as doing so due to planned venting operations which are being carried out on purpose).

The suppression chamber is technically part of the core's primary containment, though in fact the core itself lives in its own central cocoon at the middle of the doughnut-shaped, water-filled suppression chamber. The plant owner, TEPCO, in conjunction with Japanese government officials, stated that the No 3 suppression chamber might have suffered damage well over a week ago: this possibility was well known. We here at the Regreported it back then, and not being goldfish we still remember doing so.

Tokyo tapwater - THE NEW GROUND ZERO!!! Fallout!!! Chernobyl!!!

Then there's the matter of the tapwater in Tokyo. Two days ago, levels of radioactive iodine-131 were found in the city's water which were above the safety limit for baby milk calculated on the basis of a year's consumption: in other words, if babies drank such water for a year constantly they would have a tiny, minuscule extra risk of thyroid cancer.

One should note that iodine-131 has a half-life of 8 days: it disappears almost completely within a matter of weeks. The Fukushima reactors have not been generating any more of it since they scrammed nearly a fortnight ago, and the residual core heating which is causing it to be emitted has plunged to tiny proportions of that seen in the days after the quake.

There was never any chance whatsoever that levels of iodine-131 in the tapwater would remain noticeable for a year, which is what would be necessary for any effects at all on the city's babies. It was really quite irresponsible of the authorities to recommend that infants shouldn't drink it. (One can't help noticing that the first such recommendation reportedly came from the city authorities, belatedly followed by the national government. The Tokyo city governor is from the national opposition party and is facing a tough re-election battle. He had previously sought to use the Fukushima situation to cast his political rivals in a bad light over the deployment of Tokyo's elite Hyper Rescue firefighters.)

The spurious water announcement, of course, caused pretty much everybody to stop drinking from Tokyo taps and there was a run on bottled water. This was reported globally under such headlines as "Tokyo Water Works is new ground zero" (since retracted, but the Google cache will show you the guilty organisation for a while) even as the announcement came that, of course, the harmless minuscule iodine-131 spike had passed.

The facts are that minuscule quantities of airborne radio-iodine and radio-caesium from Fukushima are now being detected by instruments all round the world - as you would expect, because radioactivity can be detected in incredibly tiny amounts. If you wanted to, you could examine weather records since the quake hit, concoct a simulation of how iodine and caesium might travel around the planet to be deposited at far-flung instruments thousands of miles away, and then plug in those final readings in order to extrapolate back to generate a figure for possible emissions from Fukushima. That figure would be highly uncertain, to put it mildly, but you could do it.

There wouldn't be a lot of point in doing so in the case of radio-caesium, as nobody has ever been able to show that this isotope has any health consequences at all: huge amounts were emitted from Chernobyl, but no discernible illnesses have resulted.

Radio-iodine, though, did have measurable (though very small) health effects after Chernobyl: if children and young people drank milk containing large amounts of it - thousands of times the levels seen in Japan to this point - their chances of getting cancer increased by approximately 0.02 per cent.

Anyway, one meteorologist has decided to try and work back from the worldwide readings to calculate possible emissions figures from Fukushima. It is these figures that New Scientist tell us are "nearing Chernobyl levels".

Fortunately we can go straight to the source here, and find that in the judgement of Gerhard Wotawa of the Austrian met office (and of the Comprehensive Test Ban Treaty Organisation) emissions of iodine-131 from Fukushima could be approximately 20 per cent of those from Chernobyl.

It should be needless to say there is not a hint of a suggestion that anybody will be giving milk with significant levels of iodine-131 in it to children, as happened to about 18 million youngsters after Chernobyl, causing them a tiny increased chance of later developing thyroid cancer (which, unusually for cancer, is easily cured - though you need supplies of radio-iodine from nuclear reactors to do so).

Sadly it does appear to be necessary to say that.

The "fallout" which is "nearing Chernobyl levels" is presumably the still more harmless radio-caesium, which Wotawa theorises may have been emitted from Fukushima in amounts "20-60" per cent of those seen at Chernobyl.

One should also add that in Wotawa's judgement all these substantial emissions of iodine and caesium have fallen into the sea: there is basically zero chance of verifying that they actually happened. Health consequences - of course - should be zero.